CVE-2026-65421: Mz Automation GmbH LIBIEC61850

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

The MMS BER decoder contains a flaw in decoding fixed-width BER fields (boolean/integer): an attacker-supplied length value is not validated, causing a read past the end of a heap buffer. This leads to termination of the MMS service process and a denial-of-service condition.

Affected products

• Mz Automation GmbH LIBIEC61850: before 1.6.2 (fixed in 1.6.2)

Published 2026-07-30. Last modified 2026-09-03.